AMMAN—Jordanian soldiers killed 27 armed smugglers on Thursday as they tried to cross the border from Syria during a dawn snowstorm with a large quantity of amphetamines, an army spokesman said. Others also carrying drugs fled back into Syria during the attempted crossing, one of a growing number of such incidents over the past year, many involving firefights, that have prompted the army to toughen its rules of engagement with smugglers. Several others among the smugglers, who were “supported by other armed groups,” were wounded, the army said in a statement. It did not specify where along the border the incursion took place. Many smugglers have favored Jordan’s main border crossing to the Gulf region, where the army has found drugs, most commonly an amphetamine known as Captagon, hidden in Syrian trucks. Jordanian officials say Lebanon’s Iran-backed Hezbollah group and militias who control much of southern Syria are behind the …